Surface acoustic wave filter and multistage filter with multiple inside busbar lead-out electrodes

A surface acoustic wave filter on a piezoelectric substrate comprising first and second surface acoustic wave resonators each having a reflector electrode on both sides of an IDT electrode as an inter-digital transducer electrode, said resonators being disposed nearby in positions in which directions of propagation of respective surface acoustic waves are parallel with each other and acoustically coupled,

• an inside bus bar electrode included in the first IDT electrode of the first surface acoustic wave resonator and an inside bus bar electrode included in the second IDT electrode of the second surface acoustic wave resonator being mutually electrically separated,
• said first IDT electrode being connected to a balanced type input terminal, and said second IDT electrode being connected to a balanced type output terminal,
• one terminal of said balanced type input terminal being electrically connected to leading out electrodes led out directly or indirectly from at least two places of the inside bus bar electrode of said first IDT electrode, and one terminal of said balanced type output terminal being electrically connected to leading out electrodes led out directly or indirectly from at least two places of the inside bus bar electrode of said second IDT electrode, thereby performing balanced operation.